Anna Canton - MASCARGON IS A CHEMICAL ELEMENT REPRESENTED BY THE SYMBOL (AR). ARGON IS THE THIRD ELEMENT IN GROUP 18 IN THE PERIODIC TABLE. ARGON IS THE THIRD MOST KNOWN AND COMMON GAS IN THE EARTHS ATMOSPHERE. THE NAME ARGON IS DILIVERED FROM THE GREEK WORD " APYOV" MEANING " THE INACTIVE ONE" A REFERENCE TO THE FACT THAT THE ELEMENT UNDERGOES ALMOST NO CHEMICAL REACTIONS. Name: Argon Symbol: Ar Type: Noble gas Automatic weight: 39.948